Heating assembly for a washing appliance

ABSTRACT

A drying system includes a tub having a plurality of walls. The tub also defines a wet chamber. The drying system also includes a heat pipe heat exchanger integrally joined to one of the plurality of walls of the tub. The drying system may be provided in a dishwashing appliance. A method of making a dishwashing appliance includes positioning a pipe within a mold and forming a portion of the dishwashing appliance over the pipe in the mold.

FIELD OF THE INVENTION

The present subject matter relates generally to washing appliances, such as dishwashing appliances and, more particularly, to a heating assembly of a washing appliance.

BACKGROUND OF THE INVENTION

Dishwashing appliances generally include a tub that defines a wash chamber. Rack assemblies can be mounted within the wash chamber for receipt of articles for washing where, e.g., detergent, water, and heat, can be applied to remove food or other materials from dishes and other articles being washed. Various cycles may be included as part of the overall cleaning process. For example, a typical, user-selected cleaning option may include a wash cycle and rinse cycle (referred to collectively as a wet cycle), as well as a drying cycle. In addition, spray-arm assemblies within the wash chamber may be used to apply or direct fluid towards the articles disposed within the rack assemblies in order to clean such articles.

Fluids used in the cleaning process may be heated. For example, hot water may be supplied to the dishwasher and/or the dishwasher may include one or more heat sources for heating fluids used in wash or rinse cycle and for providing heat during a drying cycle. It is common to provide dishwashers with rod-type, resistive heating elements in order to supply heat within the wash chamber during one or more of the dishwasher cycles (e.g. during the drying cycle). Generally, these heating elements include an electric resistance-type wire that is encased in a ceramic-filled, metallic sheath. The usage of such electric heaters typically leads to increased energy consumption. Moreover, a significant portion of the energy used to heat the water, e.g., for the wash cycle, may be wasted when the hot water is discharged from the dishwasher after being applied to the articles. Additionally, the placement of heating elements within the tub may create potential leak points, for example, where a heating element or associated components such as a power supply pass through the tub.

Accordingly, an improved heating device for a dishwashing appliance that provides for improved energy usage would be welcomed in the technology. Also, an improved heating device which reduces potential leak points would be welcomed in the technology.

BRIEF DESCRIPTION OF THE INVENTION

The present invention provides a drying system including a heat pipe heat exchanger which is integrally joined with a wall or other component, such as a wall of a sump of a dishwashing appliance. As used herein, the heat pipe heat exchanger is “integrally joined” to the wall or other component in that the component and the heat pipe heat exchanger are joined together in a liquid-tight connection without the use of fasteners. For example, the heat pipe heat exchanger may be integrally joined to the wall by overmolding the wall onto the heat pipe heat exchanger. Additional aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

In one embodiment a dishwashing appliance is provided. The dishwashing appliance includes a tub having a plurality of walls. The tub also defines a wash chamber. The dishwashing appliance also includes at least one spray-arm assembly positioned within the wash chamber and a fluid circulation system configured to deliver fluid to the at least one spray-arm assembly. A sump is positioned at a bottom of the wash chamber for receiving fluid from the wash chamber. The sump includes a sump chamber having a sidewall and a base wall. The dishwashing appliance also includes a drying system. The drying system includes a heat pipe heat exchanger. The heat pipe heat exchanger includes a condenser section and an evaporator section. The condenser section is in operative communication with an inlet of the wash chamber. The heat pipe heat exchanger is integrally joined to one of the tub, the sump, and the fluid circulation system.

In another embodiment, a method of making a dishwashing appliance is provided. The method includes positioning a pipe within a mold and forming a portion of the dishwashing appliance over the pipe in the mold.

In another embodiment, a drying system is provided. The drying system includes a tub having a plurality of walls. The tub also defines a wet chamber. The drying system also includes a heat pipe heat exchanger integrally joined to one of the plurality of walls of the tub.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

FIG. 1 illustrates a front view of one embodiment of a dishwashing appliance as may incorporate one or more embodiments of the present subject matter.

FIG. 2 illustrates a section view of the dishwashing appliance shown in FIG. 1, particularly illustrating various internal components of the dishwashing appliance.

FIG. 3 provides a section view of a dishwashing appliance including a drying system according to one or more embodiments of the present subject matter.

FIG. 4 provides an enlarged view of a portion of the dishwashing appliance of FIG. 3.

FIG. 5 provides a section view of a dishwashing appliance including a drying system according to one or more additional embodiments of the present subject matter.

FIG. 6 provides a section view of a portion of the dishwashing appliance of FIG. 5 taken along line 6-6 in FIG. 5.

FIG. 7 provides a perspective view of a heat pipe heat exchanger as may be incorporated into a drying system according to one or more embodiments of the present subject matter.

FIG. 8 provides a section view of a dishwashing appliance including a drying system according to one or more additional embodiments of the present subject matter.

FIG. 9 provides a flow chart illustrating a method of making a dishwashing appliance in accordance with at least one embodiment of the present subject matter.

FIG. 10 provides a flow chart illustrating a method of making a dishwashing appliance in accordance with at least one embodiment of the present subject matter.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The terms “upstream” and “downstream” refer to the relative direction with respect to fluid flow in a fluid pathway. For example, “upstream” refers to the direction from which the fluid flows, and “downstream” refers to the direction to which the fluid flows.

Referring now to the drawings, FIGS. 1 and 2 illustrate one embodiment of a domestic dishwashing appliance 100 that may be configured in accordance with aspects of the present disclosure. The dishwashing appliance 100 may define a vertical direction V (FIGS. 1 and 2), a lateral direction L (FIG. 1) and a transverse direction T (FIG. 2). The vertical, lateral, and transverse directions V, L, and T are mutually perpendicular and form an orthogonal coordinate system. As shown in FIGS. 1 and 2, the dishwashing appliance 100 may include a cabinet 102 having a tub 104 therein defining a wash chamber 106. The tub 104 may generally include a front opening (not shown) and a door 108 hinged at its bottom 110 for movement between a normally closed vertical position (shown in FIGS. 1 and 2), wherein the wash chamber 106 is sealed shut for washing operation, and a horizontal open position (not shown) for loading and unloading of articles from the dishwasher. As shown in FIG. 1, a latch 123 may be used to lock and unlock the door 108 for access to the chamber 106.

As is understood, the tub 104 may generally have a rectangular cross-section defined by various wall panels or walls. For example, as shown in FIG. 2, the tub 104 may include a top wall 160 and a bottom wall 162 spaced apart from one another along the vertical direction V of the dishwashing appliance 100. Additionally, the tub 104 may include a plurality of sidewalls 164 (e.g., four sidewalls) extending between the top and bottom walls 160, 162. It should be appreciated that the tub 104 may generally be formed from any suitable material. However, in several embodiments, the tub 104 may be formed from a ferritic material, such as stainless steel, or a polymeric material.

As particularly shown in FIG. 2, upper and lower guide rails 124, 126 may be mounted on opposing side walls 164 of the tub 104 and may be configured to accommodate roller-equipped rack assemblies 130 and 132. Each of the rack assemblies 130, 132 may be fabricated into lattice structures including a plurality of elongated members 134 (for clarity of illustration, not all elongated members making up assemblies 130 and 132 are shown in FIG. 2). Additionally, each rack 130, 132 may be adapted for movement along the transverse direction T between an extended loading position (not shown) in which the rack is substantially positioned outside the wash chamber 106, and a retracted position (shown in FIGS. 1 and 2) in which the rack is located inside the wash chamber 106. This may be facilitated by rollers 135 and 139, for example, mounted onto racks 130 and 132, respectively. As is generally understood, a silverware basket (not shown) may be removably attached to rack assembly 132 for placement of silverware, utensils, and the like, that are otherwise too small to be accommodated by the racks 130, 132.

Additionally, the dishwashing appliance 100 may also include a lower spray-arm assembly 144 that is configured to be rotatably mounted within a lower region 146 of the wash chamber 106 directly above the bottom wall 162 of the tub 104 so as to rotate in relatively close proximity to the rack assembly 132. As shown in FIG. 2, a mid-level spray-arm assembly 148 may be located in an upper region of the wash chamber 106, such as by being located in close proximity to the upper rack 130. Moreover, an upper spray assembly 150 may be located above the upper rack 130.

As is generally understood, the lower and mid-level spray-arm assemblies 144, 148 and the upper spray assembly 150 may generally form part of a fluid circulation system 152 for circulating fluid (e.g., water and dishwasher fluid which may also include water, detergent, and/or other additives, and may be referred to as wash liquid) within the tub 104. As shown in FIG. 2, the fluid circulation system 152 may also include a recirculation pump 154 located in a machinery compartment 140 below the bottom wall 162 of the tub 104, as is generally recognized in the art, and one or more fluid conduits for circulating the fluid delivered from the pump 154 to and/or throughout the wash chamber 106. The tub 104 may include a sump 142 positioned at a bottom of the wash chamber 106 for receiving fluid from the wash chamber 106. The recirculation pump 154 receives fluid from sump 142 to provide a flow to fluid circulation system 152, which may include a switching valve or diverter (not shown) to select flow to one or more of the lower and mid-level spray-arm assemblies 144, 148 and the upper spray assembly 150.

Moreover, each spray-arm assembly 144, 148 may include an arrangement of discharge ports or orifices for directing washing liquid onto dishes or other articles located in rack assemblies 130 and 132, which may provide a rotational force by virtue of washing fluid flowing through the discharge ports. The resultant rotation of the lower spray-arm assembly 144 provides coverage of dishes and other dishwasher contents with a washing spray.

A drain pump 156 may also be provided in the machinery compartment 140 and in fluid communication with the sump 142. The drain pump 156 may be in fluid communication with an external drain (not shown) to discharge fluid, e.g., used wash liquid, from the sump 142.

The dishwashing appliance 100 may be further equipped with a controller 137 configured to regulate operation of the dishwasher 100. The controller 137 may generally include one or more memory devices and one or more microprocessors, such as one or more general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with a cleaning cycle. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor.

The controller 137 may be positioned in a variety of locations throughout dishwashing appliance 100. In the illustrated embodiment, the controller 137 is located within a control panel area 121 of the door 108, as shown in FIG. 1. In such an embodiment, input/output (“I/O”) signals may be routed between the control system and various operational components of the dishwashing appliance 100 along wiring harnesses that may be routed through the bottom of the door 108. Typically, the controller 137 includes a user interface panel/controls 136 through which a user may select various operational features and modes and monitor progress of the dishwasher 100. In one embodiment, the user interface 136 may represent a general purpose I/O (“GPIO”) device or functional block. Additionally, the user interface 136 may include input components, such as one or more of a variety of electrical, mechanical or electro-mechanical input devices including rotary dials, push buttons, and touch pads. The user interface 136 may also include a display component, such as a digital or analog display device designed to provide operational feedback to a user. As is generally understood, the user interface 136 may be in communication with the controller 137 via one or more signal lines or shared communication busses. It should be noted that controllers 137 as disclosed herein are capable of and may be operable to perform any methods and associated method steps as disclosed herein.

It should be appreciated that the present subject matter is not limited to any particular style, model, or configuration of dishwashing appliance. The exemplary embodiment depicted in FIGS. 1 and 2 is simply provided for illustrative purposes only. For example, different locations may be provided for the user interface 136, different configurations may be provided for the racks 130, 132, and other differences may be applied as well.

Turning now to FIGS. 3 through 8, an exemplary drying system 200 may be provided in order to promote drying of a wet chamber and/or of wet articles therein. The wet chamber includes a plurality of walls and the drying system includes a heat pipe heat exchanger integrally joined to one of the plurality of walls. In some embodiments, e.g., FIGS. 3 through 6, the heat pipe heat exchanger extends through the wall. In additional embodiments, e.g., FIG. 8, the heat pipe heat exchanger is surrounded by the wall. A heat pipe heat exchanger, hereinafter referred to as a “heat pipe,” is an efficient means of transferring thermal energy, e.g., heat, from one location to another. The drying system 200 may include heat pipe 202, as described in more detail hereinbelow, which captures heat from a first fluid at one end and uses the captured heat for heating a second fluid on the other end. For example, the first fluid may be, e.g., water in a water storage chamber or air in an air conduit, and the second fluid may be an air stream. For example, in some embodiments, the wet chamber may be the wash chamber 106 of dishwashing appliance 100 and wet articles, e.g., dishes, may be located therein. In such embodiments, the water storage chamber may be the sump 142 of the dishwashing appliance 100. In additional embodiments, the air conduit may be an exhaust conduit of the dishwashing appliance 100. In embodiments where the drying system 200 is provided as part of a dishwashing appliance 100, the heat pipe 202 may advantageously be the only heat source for the drying cycle, e.g., the dishwasher appliance 100 may not include a resistance heating element and/or may not use a resistance heating element during the drying cycle. Further, in embodiments wherein the drying system 200 is part of dishwasher appliance 100 and the first fluid is water in the sump 142, the operation of the dishwasher appliance 100 may include holding liquid in the sump 142 during the drying cycle. That is, rather than activating the drain pump 156 (FIG. 2) shortly after the wet cycle is complete and draining out the hot liquid from the sump 142, the liquid may be retained within the appliance, e.g., within the sump 142 of dishwasher appliance 100 in order to extract thermal energy from the liquid for the drying cycle before discharging the liquid from the sump 142.

In additional embodiments, the drying system 200 may be provided in other appliances or devices, such as a clothes dryer appliance, desiccator, or any other appliance or device wherein drying is desired.

The heat pipe 202 includes a sealed casing 204 containing a working fluid 206 (FIG. 4) in the casing 204. The casing 204 is a tubular structure and may, in some embodiments, have a generally circular cross-section. In other embodiments, the cross-section of the casing 204 may be, e.g., octagonal or otherwise polygonal, oval, or any other suitable shape. In some embodiments, the working fluid 206 may be water. In other embodiments, suitable working fluids for the heat pipe 202 include acetone, methanol, ethanol, or toluene. In other embodiments, any suitable fluid may be used for working fluid 206, e.g., that is compatible with the material of the casing 204 and is suitable for the desired operating temperature range. As seen in FIGS. 3 and 5, the heat pipe 202 extends between a condenser section 208 and an evaporator section 210. The working fluid 206 contained within the casing 204 of the heat pipe 202 absorbs thermal energy at the evaporator section 210, whereupon the working fluid 206 travels in a gaseous state from the evaporator section 210 to the condenser section 208. The gaseous working fluid 206 condenses to a liquid state and thereby releases thermal energy at the condenser section 208. A plurality of fins 212 may be provided on an exterior surface of the casing 204 at one or both of the condenser section 208 and the evaporator section 210. The fins 212 may provide an increased contact area between the heat pipe 202 and air flowing around the heat pipe 202 for improved transfer of thermal energy.

The heat pipe 202 may include an internal wick structure 209 (FIG. 4) to transport liquid working fluid 206 from the condenser section 208 to the evaporator section 210 by capillary flow. In some embodiments, the heat pipe 202 may be constructed and arranged such that the liquid working fluid 206 returns to the evaporator section 210 either partially or solely by gravity flow. For example, as illustrated in FIGS. 4 and 5, the heat pipe 202 may be arranged such that the condenser section 208 is positioned above the evaporator section 210 along the vertical direction V whereby condensed working fluid 206 in a liquid state may flow from the condenser section 208 to the evaporator section 210 at least in part by gravity. In some embodiments where the liquid working fluid 206 may return to the evaporator section 210 solely by gravity, e.g., as in FIG. 5, the wick structure 209 may be omitted. Thus, the embodiments of FIGS. 4 and 5 may advantageously provide a reduced cost and simpler heat pipe 202 by reducing or omitting the wick structure 209. Other embodiments, such as is illustrated in FIG. 3, may advantageously provide a relatively shorter overall length heat pipe 202 which may promote an increased efficiency of thermal transfer as compared to a longer heat pipe. The length of the heat pipe 202 may generally be defined with respect to the distance, along a centerline 226 (FIG. 4) of the heat pipe 202, between the condenser section 208 and the evaporator section 210, e.g., the distance that the working fluid 206 may travel in operation of the heat pipe 202.

As shown in FIGS. 3 and 5, a fan 216 may be provided, e.g., proximate the condenser section 208 of the heat pipe 202. One of skill in the art will recognize that the heat pipe 202 may be activated when the fan 216 operates, e.g., when the fan 216 urges air about the condenser section 208 such that thermal energy is transferred from the condenser section 208 to the air. As the working fluid 206 in the condenser section 208 becomes relatively cool the working fluid 206 will condense and flow in liquid form to the evaporator section 210, e.g., by gravity and/or capillary flow. Thus, as one of ordinary skill would recognize, the heat transfer may be initiated upon activating the fan 216 and thereby activating the heat pipe 202. Accordingly, at times when transfer of heat from the first fluid, e.g., liquid in the sump 142, is not desired, e.g., during a wash cycle of the dishwasher appliance 100, the heat pipe 202 may be inactive when the fan 216 is not operating.

As illustrated in FIGS. 3 and 5, the tub 104 may include an inlet 214 defined in the tub 104. The inlet 214 may provide fluid communication into the wet chamber, e.g., the wash chamber 106 in embodiments where the drying system 200 is provided in a dishwashing appliance 100. Inlet 214 may be immediately proximate to and in direct fluid communication with the wet chamber, e.g., wash chamber 106. The drying system 200 may also include a fan 216 configured to urge hot air 12 through the inlet 214. For example, in some embodiments, the fan 216 may be configured to urge air from an ambient environment through the inlet 214, e.g., as illustrated in FIG. 5. As another example, in other embodiments, the fan 216 may be configured to urge air from a heating conduit 218 through the inlet 214, e.g., as illustrated in FIG. 3. In various embodiments, the condenser section 208 of the heat pipe 202 may be in operative communication with the inlet 214 upstream of the wet chamber, e.g., chamber 106. For example, as illustrated in FIG. 5, the condenser section 208 may be positioned at or proximate to the inlet 214. In other embodiments, for example as illustrated in FIG. 3, the condenser section 208 may be spaced apart from the inlet 214 and in operative communication with the inlet 214 via an intermediate structure, such as the heating conduit 218 illustrated in FIG. 3. In some embodiments, the evaporator section 210 of the heat pipe 202 may be in operative communication with the water storage chamber, e.g., sump 142, as illustrated in FIG. 3. In other embodiments, as illustrated in FIG. 5, the evaporator section 210 of the heat pipe 202 may be in operative communication with warm air in exhaust conduit 240.

The flow of hot dry air 12 may travel through the wet chamber, e.g., in embodiments where the wet chamber is wash chamber 106, to promote drying of dishes or other articles located in rack assemblies 130 and 132 within the wash chamber 106, whereupon the hot dry air 12 imparts thermal energy to and receives moisture from the articles and/or the wash chamber 106. As used herein, “hot air” includes air having a temperature of at least about 90° F., such as at least about 100° F., such as between about 100° F. and about 160° F., such as between about 115° F. and about 155° F., such as about 135° F. As used herein, terms of approximation, such as “generally,” or “about” include values within ten percent greater or less than the stated value. For example, “about 135° F.” includes from 121.5° F. to 148.5° F. As used herein, “dry air” includes air having a relative humidity less than about twenty percent, such as less than about fifteen percent, such as less than about ten percent, such as less than about five percent, such as about zero.

Where the evaporator section 210 of the heat pipe 202 is in operative communication with the water storage chamber, the temperature of the hot dry air 12 will be approximately the same as the temperature of the liquid in the sump 142, depending at least in part on the efficiency of the heat pipe 202. For example, where the water storage chamber is a sump 142 of dishwasher appliance 100, the temperature of the wash liquid stored in the sump may be about 150° F. to about 160° F. In such embodiments, depending on the dimensions of the heat pipe 202, e.g., the length and diameter of the heat pipe 202, and the type of working fluid 206, the hot air 12 may be anywhere within the temperature ranges set forth above, but will generally be less than the temperature of the liquid in the water storage chamber, e.g., sump 142.

Referring now to FIGS. 3 and 4, the drying system 200 may include a heating conduit 218 extending between the water storage chamber, e.g., sump 142, and the inlet 214. In some embodiments, the heat pipe 202 may be positioned so that the evaporator section 210 may be in operative communication with a water storage chamber, e.g., sump 142, and the condenser section 208 may be in operative communication with heating conduit 218. As best seen in FIG. 4, the sump 142 may include a sidewall 145 and a base wall 147. The heat pipe 202 may extend through at least one of the walls 145 and 147 of the sump 142. The heating conduit 218 may be configured to provide a flow of air to the condenser section 208 of the heat pipe 202. Thus, it is to be understood that the heating conduit 218 is generally not in fluid communication with the sump 142 such that liquid from the sump 142 generally will not enter the heating conduit 218. The heating conduit 218 may be in thermal communication with the sump 142. In particular, when the fan 216 is operating such that the heat pipe 202 is activated, the heating conduit 218 may be in thermal communication with the sump 142 via the heat pipe 202. Thus, the heating conduit 218 may be in fluid communication with the inlet 214 and may be in thermal communication with the sump 142. As such, the heating conduit 218 may provide thermal communication between the sump 142 and the inlet 214. The heating conduit 218 may provide thermal communication between the heat pipe 202 and the inlet 214 into the wash chamber 106. The heating conduit 218 may provide fluid communication, e.g., in the form of a stream of air 12, from the condenser section 208 of the heat pipe 202 to the inlet 214 of the tub 104. The heating conduit 218 may include an upstream end 220 and a downstream end 222 spaced apart from the upstream end 220. The condenser section 208 of the heat pipe 202 may be positioned at the upstream end 220 of the heating conduit 218. The fan 216 may be positioned proximate to the condenser section 208, e.g., the fan 216 may be positioned in the upstream end 220 of the heating conduit 218. The downstream end 222 of the heating conduit 218 may be positioned at the inlet 214, e.g., the downstream end 222 may be in direct fluid communication with the inlet 214. As noted above, the heat pipe 202 may be activated when the fan 216 operates, e.g., when the fan 216 urges air 12 through the heating conduit 218 such that thermal energy is drawn from the condenser section 208.

As shown in FIGS. 3 and 4, the heat pipe 202 may extend through at least one wall. For example, as illustrated in FIG. 4, the heat pipe 202 extends through sidewall 145 of sump 142. The heat pipe 202 may be integrally joined to the sidewall 145. As used herein, the heat pipe 202 is “integrally joined” to the sidewall 145 in that the sidewall 145 and the heat pipe 202, in particular an outer surface of the casing 204, are joined together in a liquid-tight connection without the use of fasteners, e.g., clamps. For example, the heat pipe 202 may be integrally joined to the sidewall 145 by constructing the heat pipe 202 and sump 142 according to any of the exemplary methods described below, e.g., by overmolding the sidewall 145 onto and around the heat pipe 202.

As best seen in FIG. 4, the sidewall 145 may include a collar 143 extending along the same direction as the heat pipe 202. The collar 143 may surround the heat pipe 202 such that the contact area between the heat pipe 202 and the sidewall 145 is increased as compared to the contact area that would be provided by the thickness of sidewall 145 alone without the collar 143. Collar 143 may also provide structural support and stability to the heat pipe 202. The collar 143 may, in some embodiments, extend about one-half of an inch (0.5″) on either side of the sidewall 145. In additional embodiments, the collar 143 may extend about one-quarter of an inch (0.25″) on either side of the sidewall 145.

As illustrated in FIG. 4, the centerline 226 of the heat pipe 202 may be within about fifteen degrees of a horizontal direction, e.g., one of the lateral direction L or the transverse direction T, such as about ten degrees from the horizontal direction, and/or may form an angle of at least five degrees with respect to the horizontal direction. In particular, the centerline 226 of the heat pipe 202 may diverge from the horizontal direction such that the condenser section 208 is above the evaporator section 210 along the vertical direction V.

As illustrated for example in FIG. 5, in some embodiments the drying system 200 may be in fluid communication with an ambient environment externally around drying system 200, e.g., in embodiments where the drying system 200 is provided in dishwasher appliance 100, the ambient environment around, e.g., in close proximity to, an exterior of the dishwashing appliance 100, such as the immediate surroundings of the dishwashing appliance 100 from which air may be drawn directly into an intake 254. The drying system 200 is also in fluid communication with a wet chamber, e.g., wash chamber 106 of dishwashing appliance 100, and thus drying system 200 may provide fluid communication between the chamber 106 and the ambient environment. It should be noted that other embodiments, e.g., as shown in FIGS. 3, 4, and 8, may also be in communication with the ambient environment in a similar manner as shown and described with respect to the exemplary embodiment of FIG. 5.

In some embodiments, for example as illustrated in FIG. 5, the inlet 214 may be in fluid communication with the ambient environment, e.g., via intake 254 and inlet conduit 252. The condenser section 208 of the heat pipe 202 may be positioned proximate to the inlet 214. In such embodiments, where the inlet 214 is in fluid communication with the ambient atmosphere, ambient air 10 may pass through intake 254, e.g., the ambient air 10 may be urged from the ambient environment through the intake 254 and into inlet conduit 252 by the fan 216, such that the ambient air 10 passes over and around the condenser section 208 to provide a flow of hot dry air 12 to the wet chamber, e.g., wash chamber 106.

Still with reference to FIG. 5, drying system 200 may include heat pipe 202 configured to capture heat from outgoing humid air at one end and use the captured heat for heating an incoming air stream on the other end. In some embodiments, the condenser section 208 of the heat pipe 202 may be in operative communication with an inlet conduit 252, e.g., as illustrated in FIG. 5, the condenser section 208 may be positioned in the inlet conduit 252 upstream of inlet 214. As illustrated for example in FIG. 5, the inlet conduit 252 may extend between intake 254 and the inlet 214. The intake 254 may be immediately proximate to and in direct fluid communication with the ambient environment. For example, ambient air 10 may pass through intake 254, e.g., the ambient air 10 may be urged from the ambient environment through the intake 254 and into intake conduit 252 by an intake fan 216, such that the ambient air 10 passes over and around the condenser section 208 to provide the flow of hot dry air 12 to the wet chamber.

The flow of hot dry air 12 may travel through the wet chamber, e.g., in embodiments where the wet chamber is wash chamber 106, to promote drying of dishes or other articles located in rack assemblies 130 and 132 within the wash chamber 106, whereupon the hot dry air 12 imparts thermal energy to and receives moisture from the articles and/or the wash chamber 106. Accordingly, an exhaust flow 16 from the wet chamber, e.g., wash chamber 106 of the dishwashing appliance 100, includes warm air 16. As used herein, “warm air” includes air having a temperature of between about 90° F. and about 140° F., such as between about 100° F. and about 130° F., such as between about 110° F. and about 120° F.

The drying system 200 may further include an exhaust conduit 240. The exhaust conduit 240 may extend between an inlet 238 proximate to and in direct fluid communication with the wet chamber, e.g., wash chamber 106, and an outlet 242 proximate to and in direct fluid communication with the ambient environment. As illustrated in FIG. 5, in some embodiments, the warm air 16 may enter exhaust conduit 240 through an inlet 238, e.g., the warm air 16 may be urged from the wet chamber, e.g., wash chamber 106, through the exhaust conduit 240 by an exhaust fan 224, such that the warm air 16 passes through the exhaust conduit and, in so doing, passes over and around the evaporator section 210. The evaporator section 210 may be in operative communication with the exhaust conduit 240, e.g., the evaporator section 210 may be positioned in the exhaust conduit 240 downstream of the wet chamber, e.g., wash chamber 106. As the warm air 16 flows around the evaporator section 210, heat from the warm air 16 may be transferred through the heat pipe 202 to the condenser section 208 for heating the incoming stream of ambient air 10. Accordingly, the temperature of the air may be reduced such that room temperature air 18 flows from the evaporator section 210 to the outlet 242. As used herein, “room temperature” includes temperatures between about 65° F. and about 75° F., such as about 70° F., such as about 72° F.

When the condenser section 208 is positioned in the inlet conduit 252 and the evaporator section 210 is positioned in the exhaust conduit 240, the heat pipe 202 extends through at least one wall, e.g., an outer wall 244 of the exhaust conduit 240. The heat pipe 202 may advantageously be integrally joined to the outer wall 244 of the exhaust conduit 240 to prevent or reduce leaks, e.g., humidity or condensation or other forms of moisture escaping from the exhaust conduit 240 at or around the connection point. As shown in FIGS. 5 and 6, the outer wall 244 of the exhaust conduit 240 may include a collar 243, similar to the collar 143 illustrated in FIG. 4 and described above.

Turning now to FIG. 6, the heat pipe 202 may include a series of grooves 203 which provide additional surface area, as compared to a smooth casing 204, for the contact surface between the heat pipe 202 and the collar, e.g., collar 243. The grooves 203 may be longitudinally oriented, e.g., generally parallel to the centerline 226 (FIG. 4) of the heat pipe 202 and may be arranged circumferentially about the heat pipe 202. The grooves 203 may have a longitudinal extent generally equivalent to the length of the collar 143 or 243. As illustrated in a perspective view in FIG. 7, the heat pipe 202 may also or instead include a knurling pattern 207 formed on the outer casing 204 to provide increased surface area of the contact surface, in similar manner as the grooves 203.

As shown in FIG. 8, the heat pipe 202 may be integrally joined to a conduit 153 of the fluid circulation system 152 (FIG. 2). For example, the conduit 153 may be a rubber conduit overmolded onto the heat pipe 202. In other embodiments, the conduit may be plastic, e.g., polypropylene, or any other suitable material, e.g., copper. As illustrated for example in FIG. 8, the conduit 153 may be connected to the sump 142 such that liquid in the sump 142 may flow into the conduit 153 and contact the evaporator section 210 of the heat pipe 202.

Further embodiments include one or more methods of making a dishwashing appliance. As illustrated in FIG. 9, in some embodiments, the method 300 may include locating or positioning a pipe within a mold at step 310. The method 300 may also include forming a portion of a tub of the dishwashing appliance over the pipe in the mold. For example, as illustrated in FIG. 9, the method 300 may include a step 320 of forming the portion of the tub by injection molding a plastic material over the pipe in the mold, e.g., to form a sump. The plastic material may, in some example embodiments, be polypropylene. In additional embodiments, any suitable plastic material may be used. In some embodiments, the pipe may be a heat pipe heat exchanger. In other embodiments, the method 300 may include a step 330 of making the pipe into a heat pipe heat exchanger by adding a working fluid to the pipe and sealing the pipe to sealingly enclose the working fluid within the pipe after forming the portion of the tub, e.g., sump. For example, where the working fluid is a fluid having a relatively low boiling point, such as acetone, it may be advantageous to add the working fluid to the pipe after overmolding the other component onto the pipe to avoid exposing the working fluid to heat during the molding process.

As illustrated in FIG. 10, in some embodiments, the method 400 may include locating or positioning a pipe within a mold at step 410. The method 400 may also include forming a portion of a tub of the dishwashing appliance over the pipe in the mold. For example, as illustrated in FIG. 10, the method 400 may include a step 420 of forming the portion of the tub by casting a metallic material over the pipe in the mold, e.g., to form an exhaust conduit. The metallic material may, in some embodiments, include copper, aluminum, or stainless steel. In other embodiments, any suitable metallic material may be used. In some embodiments, the pipe may be a heat pipe heat exchanger. In other embodiments, the method 400 may include a step 430 of making the pipe into a heat pipe heat exchanger by adding a working fluid to the pipe and sealing the pipe to sealingly enclose the working fluid within the pipe after forming the portion of the tub, e.g., exhaust conduit. As mentioned above, it may be advantageous to avoid exposing the working fluid, e.g., acetone, to heat while casting the metallic material in the mold. Various combinations of the exemplary methods described herein are also possible. For example, the exhaust conduit may be formed of a plastic material injection molded over and around the heat pipe. Additional other modification, variations, and combinations are also possible, as would be understood by one of ordinary skill in the art.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 

What is claimed is:
 1. A dishwashing appliance, comprising: a tub comprising a plurality of walls, the tub defining a wash chamber; at least one spray-arm assembly positioned within the wash chamber; a fluid circulation system configured to deliver fluid to the at least one spray-arm assembly; a sump positioned at a bottom of the wash chamber for receiving fluid from the wash chamber, the sump comprising a sump chamber having a sidewall and a base wall; and a drying system, the drying system comprising a heat pipe heat exchanger, the heat pipe heat exchanger comprising a condenser section and an evaporator section, the condenser section in operative communication with an inlet of the wash chamber, the heat pipe heat exchanger integrally joined to one of the tub, the sump, and the fluid circulation system.
 2. The dishwasher appliance of claim 1, wherein heat pipe heat exchanger extends through and is integrally joined to one of the sidewall and the base wall of the sump.
 3. The dishwasher appliance of claim 2, wherein the evaporator section of the heat pipe heat exchanger is in operative communication with the sump.
 4. The dishwasher appliance of claim 1, wherein the tub comprises an exhaust conduit in fluid communication with the wash chamber, and heat pipe heat exchanger extends through and is integrally joined to a wall of the exhaust conduit.
 5. The dishwasher appliance of claim 5, wherein the evaporator section of the heat pipe heat exchanger is in operative communication with the exhaust conduit downstream of the wash chamber.
 6. The dishwashing appliance of claim 1, wherein the heat pipe heat exchanger is integrally joined to a conduit of the fluid circulation system.
 7. The dishwashing appliance of claim 1, further comprising a heating conduit, the condenser section of the heat pipe heat exchanger in operative communication with the heating conduit.
 8. A method of making a dishwashing appliance, the method comprising: positioning a pipe within a mold; and forming a portion of the dishwashing appliance over the pipe in the mold.
 9. The method of claim 8, wherein the portion of the dishwashing appliance is a sump.
 10. The method of claim 8, wherein the portion of the dishwashing appliance is an exhaust conduit.
 11. The method of claim 8, wherein forming the portion of the tub comprises injection molding a plastic material over the pipe in the mold.
 12. The method of claim 8, wherein forming the portion of the tub comprises casting a metallic material over the pipe in the mold.
 13. The method of claim 8, wherein the pipe is a heat pipe heat exchanger.
 14. The method of claim 8, further comprising making the pipe into a heat pipe heat exchanger by adding a working fluid to the pipe and sealing the pipe to sealingly enclose the working fluid within the pipe after forming the portion of the tub.
 15. A drying system, comprising: a tub comprising a plurality of walls, the tub defining a wet chamber; and a heat pipe heat exchanger integrally joined to one of the plurality of walls of the tub.
 16. The drying system of claim 15, wherein the tub comprises a water storage chamber and the one of the plurality of walls of the tub comprises a wall of the water storage chamber.
 17. The drying system of claim 16, wherein the wet chamber is a wash chamber of a dishwasher appliance, and the water storage chamber comprises a sump positioned at a bottom of the wash chamber for receiving fluid from the wash chamber.
 18. The drying system of claim 16, wherein the heat pipe heat exchanger comprises a condenser section and an evaporator section, the evaporator section in operative communication with the water storage chamber.
 19. The drying system of claim 15, wherein the tub comprises an exhaust conduit in fluid communication with the wet chamber, and the one of the plurality of walls of the tub comprises a wall of the exhaust conduit.
 20. The drying system of claim 15, wherein the heat pipe heat exchanger comprises a condenser section and an evaporator section, the evaporator section in operative communication with the exhaust conduit downstream of the wet chamber. 